Apple Rhubarb Cake

2 cups rhubarb [diced]
3 cups apple pie filling
1 packet strawberry gelatin mix
1 cup sugar
1 teaspoon cinnamon [ground]
1 packet white cake mix
3 cups mini-marshmallows

Mix the fruit together and put in the bottom of 9 x 11 inch glass cake/baking pan. Mix the gelatin, sugar and, cinnamon, pour over the fruit, cover with the marshmallows, then pour the cake mix on top of everything. Bake in a 350 degree oven for 45 to 50 minutes. Cool to room temperature and then refrigerate till ready to serve. Garnish as desired.